Wireless mobile communication technology uses various standards and protocols to transmit data between a node (e.g., a transmission station) and a wireless device (e.g., a mobile device). Some wireless devices communicate using orthogonal frequency-division multiple access (OFDMA) in a downlink (DL) transmission and single carrier frequency division multiple access (SC-FDMA) in an uplink (UL) transmission. Standards and protocols that use orthogonal frequency-division multiplexing (OFDM) for signal transmission include the third generation partnership project (3GPP) long term evolution (LTE), the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard (e.g., 802.16e, 802.16m), which is commonly known to industry groups as WiMAX (Worldwide interoperability for Microwave Access), and the IEEE 802.11 standard, which is commonly known to industry groups as WiFi. In 3GPP radio access network (RAN) LTE systems, the node can be a combination of Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node Bs (also commonly denoted as evolved Node Bs, enhanced Node Bs, eNodeBs, or eNBs) and Radio Network Controllers (RNCs), which communicates with the wireless device, known as a user equipment (UE). The downlink (DL) transmission can be a communication from the node (e.g., eNodeB) to the wireless device (e.g., UE), and the uplink (UL) transmission can be a communication from the wireless device to the node.
Next generation of cellular standard, long-term evolution, advanced (LTE-A), have adopted many capacity-enhancing technologies, including coordinated multi-point transmission/reception (CoMP), multi-user multi-input multi-output (MU-MIMO), and heterogeneous networks (HetNet) to improve wireless network discover, cell capacity and reduce interference.
For example, interference is a major source of performance degradation in cellular systems. Massive MIMO using very large antenna arrays is used to substantially reduce interference and increase throughput. In the massive MIMO technique, a base station equipped with a specified number, such as, for example, a few hundred, transmit antennas transmits data to a plurality of mobile stations with a multi-user MIMO scheme. Higher number of antenna elements in a closely spaced antenna configuration enhances angular and spatial resolution by producing narrow and directive beams, thereby mitigating the interference. Coordinated Multi-Point (CoMP) is another technique to combat interference particularly for cell-edge cellular users wherein interfering transmitting points cooperate to boost average and cell-edge throughputs.
The Massive MIMO systems, having a large number of antennas, can increase spectral efficiency by potentially reducing the interference and enabling more number of users to be spatially multiplexed. However, despite using beamforming to enable operation in mid-to-high frequency bands, channel blockage is a current challenge for mid-to-high frequency bands thereby reducing efficiency and the ability to support seamless mobility.
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the technology is thereby intended.